A Dropbox disaster | Dafacto

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A Dropbox disaster

01 October 2014

I'm in the process of recovering from a Dropbox disaster, and wanted to document it here in case it may prove useful to others.

I have Dropbox running under the same account on two computers, my MacBook Air and a Mac mini. In that Dropbox, I have close to 100GB of data, across approximately 100,000 files, organized in a deep folder structure.

Last week, on the MacBook Air, I did a major reorganization of the folder structure within Dropbox, that probably affected the locations of 50% of my files.

Dropbox running on the Mac mini soon detected the changes, and began the process of updating its own files. It appears that the first step is that process is the creation of all the folders which form the new directory structure, at which point it begins creating (or moving?) all the files into place.

At some point during this folder creation and file shuffling process, the external hard drive attached to the Mini, on which the Dropbox folder lives, died. In theory, this shouldn't be a disaster. It practice, it turned out to be.

I replaced the drive with a new one and used CrashPlan to restore all its contents, including the Dropbox folder. Once the restore was completed, I launched Dropbox and walked away from the machine—thinking it'd naturally take a while for Dropbox to figure out where it was in the previous file-shuffling process, and get back to work doing its thing.

About a day later, noticing some files missing from Dropbox on the MacBook Air, I discovered that many of its folders were completely empty. Logging into Dropbox's website, navigating to some of those empty folders, and clicking the "Show Deleted Files" icon, I saw all the files I expected to be there had been deleted. And looking at the "Events" screen at Dropbox.com, I saw that within the past 24 hours, over 40,000 files had been deleted!

Upon further investigation, I discovered that Dropbox (the server) somehow viewed the current state of the Dropbox folder on the Mac mini's restored drive as authoritative, and then began updating my MacBook Air to match. Remember, at the time the drive died, Dropbox on the mini had created the new folder structures to match the reorganization on my MacBook Air (and removed the folders in the old locations), but had not yet created many of the files which belonged in those folders.

As I write this blog post, I'm in the process of trying to recover from this. My plan is to:

  1. Completely delete the Dropbox folder from the Mac mini.
  2. Recover a copy of my MacBook Air's Dropbox in its state as of last week, using CrashPlan.
  3. Merge those Dropbox contents into Dropbox on the MacBook Air, hopefully bringing it back to the state when it first started communicating its reorganization to the Dropbox servers. (I can't just replace all the contents, since I've since created some new files and modified others.)
  4. Once Dropbox reports itself being up to date, I'll re-create Dropbox on the Mac mini, as a fresh install, and let it initialize itself from the server. (LAN sync will help get all the files transferred in quickly.)

I'll report back here with the results.

Update 2014-10-06

The recovery plan worked, and my Dropbox has been restored. The lesson here is that I should not have included Dropbox in my restore of the crashed drive. Instead, I should have restored everything else, and then let Dropbox restore itself from a fresh install.

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